Orthodontic bracket

ABSTRACT

In one embodiment, a pre-engaging orthodontic bracket includes a body having a lingual surface for attachment to a tooth, a pair of laterally spaced gingival tie wings and a pair of laterally spaced occlusal tie wings. The gingival and occlusal tie wings project from a labial surface of the body. An archwire slot extends mesiodistally across the body and between the gingival and occlusal tie wings at opposed mesial and distal sides of the body to accommodate an archwire. A pivot pin extends between a pair of the tie wings at opposed mesial and distal sides of the body. A shutter is moveable relative to the body between an open position in which placement and removal of an archwire into the archwire slot is facilitated and a closed position in which placement and removal of an archwire into the archwire slot is inhibited.

RELATED APPLICATIONS

This patent application is a continuation of prior U.S. application Ser.No. 09/847,505, filed on May 2, 2001, pending; which is a continuationof U.S. application Ser. No. 09/327,732, filed on Jun. 8, 1999, now U.S.Pat. No. 6,257,883; which is a continuation of U.S. application Ser. No.08/745,512, filed on Nov. 12, 1996, now U.S. Pat. No. 5,913,680; whichis a continuation in part of U.S. application Ser. No. 08/412,338, filedon Mar. 31, 1995, now abandoned; which is a continuation-in-part of U.S.application Ser. No. 08/206,724, filed on Mar. 7, 1994, now U.S. Pat.No. 5,474,445.

FIELD OF THE INVENTION

The present invention relates in general to pre-engaging orthodonticbrackets and in particular to a pre-engaging twin orthodontic bracketand to a plurality of orthodontic brackets forming a set of braces.

BACKGROUND OF THE INVENTION

According to established orthodontic techniques, it is well known thatone is able to ligate an archwire to a bracket utilizing an elastic,elastomeric or metal ligature. In a twin edgewise orthodontic bracket,the elastic ligature is stretched around respective undercuts ofgingival and occlusal tie wings so as to overlay the archwire at mesialand distal ends of the bracket.

The ligating procedure involves carefully stretching the elastic orelastomeric ligature (or wrapping and twisting a metal ligature) aroundthe tie wings utilizing appropriate orthodontic instruments. It has beenfound that the time-consuming ligation procedure contributes to lengthychair time. Furthermore, the elastic ligatures are known to lose theirelasticity with time and are subject to degradation. Also, the elasticand metal ligatures have been known to trap food particles in areas ofthe bracket which are difficult for the patient to clean, and toincrease the level of friction against the archwire. Finally, the use ofsharp metal ligatures around the bracket can subject the clinician tounnecessary exposure to infectious bacteria, or viruses such ashepatitis B, or possibly the HIV virus particularly in blood.

In an effort to overcome these disadvantages of elastic ligatures,certain advances have been made in the area of pre-engaging orthodonticbrackets. Each of U.S. Pat. Nos. 4,144,642; 4,248,588; 4,698,017;3,772,787; 4,786,242; 4,559,012; 4,561,844; 4,655,708; 4,077,126;4,419,078; 4,634,661; 4,197,642; and 4,712,999 illustrate one or moredesigns of pre-engaging brackets. These prior art devices overcome someof the disadvantages associated with elastic ligatures. For example,pre-engaging orthodontic brackets eliminate, or at least reduce,exposure of the clinician to sharp ligatures, thereby alleviating theproblem of contracting harmful bacteria or viruses. In addition,pre-engaging orthodontic brackets permit continuous low deflectiondifferential archwire contact separately for both round and rectangulararchwires at at least two different levels of contact, which is notpossible with degrading elastic, elastomeric or rigid, high deflectionmetal ligatures. However, most of the known prior art pre-engagingorthodontic brackets lack the reliability and the accessible ease ofoperability that most clinicians require. In addition, the majority ofprior art pre-engaging orthodontic brackets are of a single design thathave three or fewer tie wings.

It is therefore an object of the present invention to provide a noveltwin pre-engaging orthodontic bracket which obviates or mitigates atleast one of the above-identified disadvantages associated with priorart orthodontic brackets.

SUMMARY OF THE INVENTION

According to one aspect of the present invention there is provided apre-engaging orthodontic bracket for attaching an archwire to a toothcomprising:

a body having a lingual surface for attachment to a tooth, a pair oflaterally spaced gingival tie wings and a pair of laterally spacedocclusal tie wings, said gingival and occlusal tie wings projecting froma labial surface of said body, both said gingival tie wings and occlusaltie wings at opposed mesial and distal sides of said body beingseparated by an interwing region of said body;

an archwire slot extending mesiodistally across said body and betweenthe gingival and occlusal tie wings at opposed mesial and distal sidesof said body to accommodate an archwire, said archwire slot beinginterrupted by said interwing region;

a locking shutter moveable relative to said body between an openposition in which placement and removal of said archwire in saidarchwire slot is facilitated and a closed position in which placementand removal of said archwire in said archwire slot is inhibited; and

biasing means carried by said locking shutter and engageable with anarchwire in said archwire slot when said locking shutter is in saidclosed position, said biasing means resiliently urging said archwireinto said archwire slot to provide a continuous corrective forcethereon.

In one embodiment, the biasing means is in the form of a leaf springsecured to the locking shutter. The leaf spring can extend mesiodistallyor occlusiogingivally. In another embodiment, the locking shutter isformed of resilient material and biases the archwire when the lockingshutter is in the closed position thereby to constitute the biasingmeans.

According to another aspect of the present invention there is provided apre-engaging orthodontic bracket for attaching an archwire to a toothcomprising:

a body having a lingual surface for attachment to a tooth, a pair oflaterally spaced gingival tie wings and a pair of laterally spacedocclusal tie wings, said gingival and occlusal tie wings projecting froma labial surface of said body, both said gingival tie wings and occlusaltie wings at opposed mesial and distal sides of said body beingseparated by an interwing region of said body;

an archwire slot extending mesiodistally across said body and betweenthe gingival and occlusal tie wings at opposed mesial and distal sidesof said body to accommodate an archwire, said archwire slot beinginterrupted by said interwing region;

a locking shutter movable relative to said body between an open positionin which placement and removal of said archwire in said archwire slot isfacilitated and a closed position in which placement and removal of saidarchwire from said archwire slot is inhibited; and

biasing means engageable with an archwire in said archwire slot whensaid locking shutter is in said closed position to urge said archwiretoward said locking shutter to provide a continuous corrective forcethereon.

In one embodiment, the biasing means is in the form of a resilientspring member extending mesiodistally along the archwire slot andsecured to the body. The spring member has at least one free end and canbe dimensioned to engage an archwire either within the archwire slot orexterior to the archwire slot. In another embodiment, the resilientspring member extends occlusiodistally across the archwire slot in theinterwing region and is secured to the body adjacent one end thereof.

In another embodiment, the biasing means is in the form of magnetizedelements within the body adjacent the archwire slot to present arepelling magnetic force to the archwire to bias the archwire towardsthe locking shutter. In yet another embodiment, the biasing means is inthe form of a pair of spring-loaded pistons accommodated by the bodyadjacent opposed mesial and distal ends of the archwire slot to urge thearchwire towards the locking shutter.

According to still yet another aspect of the present invention there isprovided a pre-engaging orthodontic bracket for attaching an archwire toa tooth comprising:

a body having a lingual surface for attachment to a tooth, a pair oflaterally spaced gingival tie wings and a pair of laterally spacedocclusal tie wings, said gingival and occlusal tie wings projecting froma labial surface of said body, both said gingival tie wings and occlusaltie wings at opposed mesial and distal sides of said body beingseparated by an interwing region of said body;

an archwire slot extending mesiodistally across said body and betweenthe gingival and occlusal tie wings at opposed mesial and distal sidesof said body to accommodate an archwire, said archwire slot beinginterrupted by said interwing region; and

a locking shutter pivotal about at least one pivot pin between an openposition in which placement and removal of said archwire in saidarchwire slot is facilitated and a closed position in which placement ofsaid archwire in said archwire slot is inhibited.

In one embodiment, the orthodontic bracket includes one pivot pinextending between the tie wings of one of the two pairs and wherein thelocking shutter includes a single loop at one end thereof to surroundthe pivot pin. In another embodiment, the orthodontic bracket includes apair of pivot pins, each accommodated by each tie wing of one of the twopairs. In this case, the locking shutter includes a pair of laterallyspaced single loops surrounding the pivot pins.

Preferably, the locking shutter includes a marker thereon to identifygenerally the center of the archwire slot when the locking shutter is inthe closed position. It is also preferred that the orthodontic bracketfurther includes a lubricating or sealing agent carried by one or moreof the body, archwire slot, locking shutter and archwire.

According to still yet another aspect of the present invention there isprovided a body for an orthodontic bracket having a mesiodistallyextending archwire slot formed therein and gingival and occlusalsurfaces shaped to deflect food debris and plaque mesially and distallytherefrom when secured to a tooth.

According to still yet another aspect of the present invention there isprovided a set of braces including a plurality of orthodontic bracketsto be attached to an individual's teeth, said braces includingself-engaging twin orthodontic brackets to be attached to the centraland lateral teeth and first and second molars of said individual andsingle orthodontic brackets to be attached to the cuspid and premolarteeth of said individual.

The present invention provides advantages in that the orthodonticbrackets provide predictability and accurate control of tooth movementwhile enhancing treatment progress. The orthodontic brackets areaesthetically pleasing due to their symmetrical designs and provide foreasier hygiene than prior art orthodontic brackets.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present invention will now be describedmore fully with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a pre-engaging twin orthodontic bracketin accordance with the present invention;

FIG. 2 a is a side elevational view of the orthodontic bracket of FIG.1;

FIG. 2 b is a side elevational view of the orthodontic bracket of FIG. 1in an open position;

FIGS. 3 a and 3 b are occlusal views of an incisor section to which theorthodontic bracket of FIG. 1 of the present invention is attached,showing low deflection moment during movement of the tooth;

FIG. 4 is a front elevational view of an orthodontic bracket of the typeshown in FIG. 1 positioned on a tooth;

FIG. 5 is a perspective view of an alternative embodiment of apre-engaging twin orthodontic bracket in accordance with the presentinvention;

FIG. 6 is a front elevational view of yet another alternative embodimentof a pre-engaging twin orthodontic bracket in accordance with thepresent invention;

FIG. 7 is a cross-sectional view of FIG. 6 taken along line 7—7;

FIG. 8 is a three-quarter perspective view of the orthodontic bracket ofFIG. 6;

FIGS. 9 a and 9 b are cross-sectional views of FIG. 8 taken along line9—9 with the shutter in closed and open positions respectively;

FIG. 10 is an enlarged cross-sectional view of a portion of theorthodontic bracket of FIG. 8 with the pivot pin omitted;

FIGS. 11 a and 11 b are perspective and front elevational viewsrespectively of a shutter forming part of the orthodontic bracket ofFIG. 6.

FIG. 12 is a front elevational view of an alternative embodiment of anorthodontic bracket in accordance with the present invention having asliding shutter;

FIG. 13 is a side elevational view of the orthodontic bracket of FIG.12;

FIG. 14 is a view similar to FIG. 12 of the orthodontic bracket showingmovement of the shutter to an open position;

FIG. 15 is a side elevational view of the orthodontic bracket of FIG. 14with the shutter in the open position;

FIG. 16 a is a perspective view of another alternative embodiment of anorthodontic bracket in accordance with the present invention having asliding shutter shown in an open position;

FIG. 16 b is a side elevational view of the orthodontic bracket shown inFIG. 16 b;

FIG. 17 a is a perspective view of the orthodontic bracket of FIG. 16 ashowing the shutter in a closed position;

FIG. 17 b is a side elevational view of the orthodontic bracket shown inFIG. 17 a;

FIG. 18 is a front elevational view of an alternative embodiment of anorthodontic bracket in accordance with the present invention;

FIG. 19 is a side elevational view of the orthodontic bracket of FIG.18;

FIG. 20 is a top plan view of the orthodontic bracket of FIG. 18;

FIG. 21 is a partially exploded three-quarter perspective view of astill yet another embodiment of an orthodontic bracket in accordancewith the present invention;

FIG. 22 is a three-quarter perspective view similar to FIG. 21 of theorthodontic bracket in a closed position;

FIG. 23 is a side elevational view of the orthodontic bracket of FIG. 22accommodating an archwire;

FIG. 24 is a side elevational view of the orthodontic bracket of FIG. 22in an open position;

FIG. 25 is a front elevational view of a further embodiment of anorthodontic bracket in accordance with the present invention having aresiliently biased locking shutter;

FIG. 26 is a side elevational view of the orthodontic bracket of FIG. 25in an open position;

FIG. 27 is a side elevational view of the orthodontic bracket of FIG. 25in a closed position;

FIG. 28 is an exploded three-quarter perspective view of yet anotheralternative embodiment of an orthodontic bracket in accordance with thepresent invention;

FIG. 29 is a three-quarter perspective view of the orthodontic bracketof FIG. 28 in a closed position;

FIG. 30 a is a side elevational view of the orthodontic bracket of FIG.29 in an open position;

FIG. 30 b is a side elevational view of the orthodontic bracket of FIG.29 in a closed position;

FIG. 31 is a three-quarter perspective view of the orthodontic bracketof FIG. 29 in the open position;

FIG. 32 is a front elevational view of yet another embodiment of anorthodontic bracket in accordance with the present invention;

FIG. 33 is a side elevational view of the orthodontic bracket of FIG.32;

FIG. 34 is an occlusal view of the orthodontic bracket of FIG. 32;

FIG. 35 is a side elevational view of a shutter forming part of theorthodontic bracket of FIG. 32;

FIG. 36 is a front elevational view of the shutter of FIG. 35;

FIG. 37 is a three-quarter perspective view of still yet a furtherembodiment of an orthodontic bracket in accordance with the presentinvention;

FIG. 38 is a front elevational view of yet another alternativeembodiment of an orthodontic bracket in accordance with the presentinvention in a closed position;

FIG. 39 is a front elevational view of the orthodontic bracket of FIG.38 in an open position;

FIG. 40 is a side elevational view of the orthodontic bracket of FIG. 38accommodating a round archwire;

FIG. 41 a is a cross-sectional view of an alternative embodiment of apivot pin and shutter for use with the orthodontic bracket of FIG. 38;

FIG. 41 is a side elevational view of the orthodontic bracket of FIG. 39accommodating a round archwire;

FIG. 42 is a front elevational view of yet another alternativeembodiment of an orthodontic bracket in accordance with the presentinvention in a closed position;

FIG. 43 is a front elevational view of the orthodontic bracket of FIG.42 in an open position;

FIG. 44 is a side elevational view of the orthodontic bracket of FIG. 42accommodating a round archwire;

FIG. 45 is a side elevational view of the orthodontic bracket of FIG. 43accommodating a round archwire;

FIG. 45 a is a front elevational view of an alternative embodiment of ashutter for use with the orthodontic bracket of FIG. 42;

FIG. 46 is a front elevational view of yet another alternativeembodiment of an orthodontic bracket in accordance with the presentinvention in a closed position;

FIG. 47 is a front elevational view of yet another alternativeembodiment of an orthodontic bracket in accordance with the presentinvention in a closed position;

FIG. 48 is an exploded three-quarter perspective view of yet anotheralternative embodiment of an orthodontic bracket in accordance with thepresent invention similar to that shown in FIGS. 28 to 31;

FIG. 49 is a three-quarter perspective view of the orthodontic bracketof FIG. 48 in a closed position;

FIG. 50 is a side elevational view of the orthodontic bracket of FIG. 49in an open position;

FIG. 51 is a side elevational view of the orthodontic bracket of FIG. 49in a closed position;

FIG. 52 is a three-quarter perspective view of the orthodontic bracketof FIG. 49 in the open position;

FIG. 53 is a front elevational view of an alternative embodiment of anorthodontic bracket in accordance with the present invention having asliding shutter similar to that shown in FIGS. 12 to 15;

FIG. 54 is a side elevational view of the orthodontic bracket of FIG.53;

FIG. 55 is a side elevational view of the orthodontic bracket of FIG. 53with the shutter in the open position;

FIG. 56 is a front elevational view of a further embodiment of anorthodontic bracket in accordance with the present invention having aresiliently biased locking shutter similar to that shown in FIGS. 25 to27;

FIG. 57 is a side elevational view of the orthodontic bracket of FIG. 56in an open position;

FIG. 58 is a side elevational view of the orthodontic bracket of FIG. 56in a closed position;

FIG. 59 is a front elevational view of yet another embodiment of anorthodontic bracket in accordance with the present invention similar tothat shown in FIGS. 32 to 36;

FIG. 60 a is a side elevational view of the orthodontic bracket of FIG.59;

FIG. 60 b is a side elevational view of the orthodontic bracket of FIG.59 in an open position;

FIG. 61 is a side elevational view of a shutter forming part of theorthodontic bracket of FIG. 59;

FIG. 62 is a front elevational view of the shutter of FIG. 61;

FIG. 63 is a front elevational view of still a further embodiment of anorthodontic bracket in accordance with the present invention with theshutter removed;

FIG. 64 is a side elevational view of the orthodontic bracket of FIG. 63with the shutter installed;

FIG. 65 is a front elevational view of the orthodontic bracket of FIG.63 with the shutter installed;

FIG. 66 is a top plan view of the orthodontic bracket of FIG. 65;

FIG. 67 is a side elevational view of the orthodontic bracket of FIG.63, similar to FIG. 64, with the shutter in an open position;

FIG. 68 is a three-quarter perspective view of the orthodontic bracketof FIG. 63;

FIG. 69 is a side elevational view of an alternative embodiment of ashutter for use with the orthodontic bracket of FIG. 63;

FIG. 70 is a side elevational view of a further alternative embodimentof a shutter for use with the orthodontic bracket of FIG. 63;

FIG. 71 is a rear elevational view of the shutter of FIG. 70;

FIG. 72 is a side elevational view of a still further embodiment of ashutter for use with the orthodontic bracket of FIG. 63;

FIG. 73 is a rear elevational view of the shutter of FIG. 72;

FIG. 74 is a front elevational view of yet another alternativeembodiment of an orthodontic bracket in accordance with the presentinvention;

FIG. 75 is a side elevational view of the orthodontic bracket of FIG. 74in a closed position;

FIG. 76 is a side elevational view of the orthodontic bracket of FIG. 75in an open position;

FIG. 77 is a cross-sectional view of FIG. 76;

FIG. 78 is a perspective view of a shutter used in the orthodonticbracket of FIG. 74;

FIG. 79 is a front elevational view of yet another alternativeembodiment of an orthodontic bracket in accordance with the presentinvention;

FIG. 80 is a perspective view of the orthodontic bracket of FIG. 79;

FIG. 81 is a side elevational view of the orthodontic bracket of FIG.79;

FIG. 82 is a side elevational view of the orthodontic bracket of FIG. 79accommodating a larger archwire;

FIG. 83 is a front elevational view of yet another alternativeembodiment of an orthodontic bracket in accordance with the presentinvention;

FIG. 84 is a side elevational view of the orthodontic bracket of FIG. 83in a closed position and accommodating an archwire;

FIG. 85 is a side elevational view of the orthodontic bracket of FIG. 83showing the initial release of the shutter;

FIG. 86 is a side elevational view of the orthodontic bracket of FIG. 83showing further movement of the shutter;

FIG. 87 is a side elevational view of the orthodontic bracket of FIG. 83showing the shutter in a fully open position;

FIG. 88 is a front elevational view of yet another alternativeembodiment of an orthodontic bracket in accordance with the presentinvention;

FIG. 89 is a perspective view of a component forming part of theorthodontic bracket of FIG. 88;

FIG. 90 is a perspective view of an alternative embodiment of thecomponent of FIG. 89;

FIGS. 91 a and 91 b are side elevational views of embodiments of anorthodontic tool;

FIG. 92 a is a front elevational view of another embodiment of anorthodontic bracket in accordance with the present invention;

FIG. 92 b is a side elevational view of the orthodontic bracket of FIG.92 a;

FIG. 92 c is a top plan view of the orthodontic bracket of FIG. 92 a;

FIG. 92 d is another side elevational view of the orthodontic bracket ofFIG. 92 a;

FIG. 93 is a perspective view of a portion of another embodiment of anorthodontic bracket in accordance the present invention;

FIG. 94 is a front elevational view of yet another embodiment of anorthodontic bracket in accordance with the present invention;

FIG. 95 is a side elevational view of still yet another alternativeembodiment of an orthodontic bracket in accordance with the presentinvention;

FIGS. 96 a and 96 b are front elevational and cross-sectional views ofanother embodiment of an orthodontic bracket in accordance with thepresent invention;

FIGS. 97 a to 97 c are front elevational, side elevational and top planviews of another embodiment of an orthodontic bracket in accordance withthe present invention;

FIGS. 98 a and 98 b are front elevational and cross-sectional views ofanother embodiment of an orthodontic bracket in accordance with thepresent invention;

FIGS. 98 c and 98 d are front and side elevational views of anotherembodiment of an orthodontic bracket in accordance with the presentinvention;

FIGS. 99 a and 99 b are front and side elevational views of anotherembodiment of an orthodontic bracket in accordance with the presentinvention;

FIGS. 100 a to 100 c are front elevational, side elevational and topplan views of another embodiment of an orthodontic bracket in accordancewith the present invention;

FIG. 100 d is a cross-sectional view of an alternative embodiment of alocking shutter retainer for the orthodontic bracket of FIG. 100 a;

FIGS. 101 a to 101 c are front elevational, side elevational and topplan views of another embodiment of an orthodontic bracket in accordancewith the present invention;

FIG. 101 d is a plan view of a locking shutter used in the orthodonticbracket of FIG. 101 a in an unfolded condition;

FIGS. 102 and 103 are front and side elevational views of anotherembodiment of an orthodontic bracket in accordance with the presentinvention;

FIG. 104 is a front elevational view of an alternative embodiment of abody for an orthodontic bracket; and

FIGS. 105 and 106 are front and side elevational views of yet anotheralternative of an orthodontic bracket in accordance with the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIGS. 1 and 2, a pre-engaging twin orthodontic bracketis shown and is generally indicated to by reference numeral 10. As canbe seen, orthodontic bracket 10 includes a body 12 and a lingualmounting pad 14 attached to the body. The mounting pad 14 has a lingualsurface to be attached to a tooth. A pair of laterally spaced gingivaltie wings 16 and a pair of laterally spaced occlusal tie wings 18 extendfrom a labial surface of the body 12. The gingival tie wings 16 and theocclusal tie wings 18 curve lingually. An archwire slot 20 extendsmesiodistally across the body and between the gingival and occlusal tiewings at opposed mesial and distal sides of the body and opens labiallyto receive an archwire 22. The archwire slot 20 is interrupted in theinterwing region 12′ of the body. A V-shaped deflection notch is formedin the gingival wall of the archwire slot 20 at its mesial and distalends extends to define mesial and distal bevelled deflection surfaces 24above the archwire slot. Resting grooves 26 are formed in the labialsurface of the wings 15 below the archwire slot 20.

A shutter 30 formed of resilient stainless steel is pivotally mounted onthe occlusal tie wings 18 and is movable between a closed position whereaccess to the archwire slot 20 is inhibited and an open position whereaccess to the archwire slot is permitted (see FIGS. 2 a and 2 b). Oneend 30 a of the shutter 30 is accommodated in undercuts 34 defined bythe occlusal tie wings 18. The end 30 a of the shutter 30 accommodatedby the undercuts 34 generally resembles an open “D” and is configured toremain in the undercuts 34 throughout movement of the shutter betweenthe open and closed positions. As the shutter 30 moves between the openand closed positions, the end 30 a of the shutter translates within theundercuts 34. An aperture 30 b is formed in the shutter 30 toaccommodate a tool to facilitate opening of the shutter.

The shutter 30 curves labially and gingivally around the occlusal tiewings 18 and then curves lingually towards the archwire slot 20. Whenthe shutter 30 is in the closed position and the archwire applies alabially directed force to the shutter 30, the gingival end 36 of theshutter 30 contacts the deflection surfaces 24 to inhibit the shutterfrom being accidentally removed from the archwire slot 20. At the sametime, the lingual surface 38 of the shutter 30 contacts the archwire 22to urge it continuously into the archwire slot 20. When the shutter 30is pivoted and translated to remove it from the archwire slot 20, thegingival end 36 can be accommodated by the resting grooves 26 to holdthe shutter in the open position although this is not necessary as shownby the dotted line in FIG. 2 b. This is due to the fact that as thecompressed shutter 30 is opened, it flexes over the occlusal tie wings18 as the shutter pivots and translates in the occlusal undercuts 34 tomaintain the shutter open. The shutter 30 can be closed using a fingerby simply pushing on the shutter until the gingival end 36 of theshutter enters the archwire slot 20 with the lingual surface 38 incontact with the archwire 22. The shutter 30 can be opened by insertinga one or two prong ligature director into the aperture 30 b and applyingan occlusally directed force on the shutter in the interwing region 12′of the body 12.

The design of the shutter 30 is such that a rectangular archwire 22 isseated to apply torque to the archwire slot 20 depending on therectangular cross-sectional shape of the archwire 22. The continuousactive seating or biasing of the archwire 22 by the shutter 30 providesfor accurate tooth movement. Referring now to FIGS. 3 a and 3 b, a tooth40 with an orthodontic bracket 10 on it is shown. In FIG. 3 a, the tooth40 is shown in an original “rotated” position while in FIG. 3 b, thetooth is shown in a final “straight” position. The designations A and Bin FIGS. 3 a and 3 b denote coupled sets of force vectors applied by theshutter 30 on the orthodontic bracket 10 and archwire. As can be seen,the archwire 22 in FIG. 3 a deflects the shutter 30 labially on theright side reducing the initial force and moment applied to the tooth 40until the shutter gradually seats itself into the archwire slot 20 asshown in FIG. 3 b with less patient discomfort.

Referring now to FIG. 4, an orthodontic bracket 10 is shown on a tooth40. The occlusal edges of the orthodontic bracket 10 are preferablyparallel to the incisal edges and parallel to the archwire slot. Twoscribe lines 44 on the orthodontic bracket 10 delineate the long axis 46of the tooth 40 for ideal placement of the orthodontic bracket. Also,the external lingual surface of the mounting pad 14 is angulated orbiased to assist alignment and placement of the orthodontic bracket 10against the long axis of the tooth. Larger brackets may be used forlarger molars.

Referring now to FIG. 5, an alternative embodiment of an orthodonticbracket is shown and is generally indicated to by reference numeral 10a. In this embodiment, like reference numerals will be used to indicatelike components of the first embodiment with an “a” added for clarity.As can be seen, the shutter 24 a is received in undercuts 34 a definedby the occlusal tie wings 18 a. The shutter 30 a has an aperture 51formed in it to receive a tool and facilitate pivoting of the shutterfrom the closed to open positions using a tool. A hollow vertical slot52 is provided on the body 12 a in the interwing region 12 a′. Thehollow slot 52 allows the orthodontic bracket 10 a to provide for moretooth inclination, torque control and overcorrection than prior artorthodontic brackets.

Referring now to FIGS. 6 to 10, yet another embodiment of a pre-engagingtwin orthodontic bracket is shown and is generally indicated to byreference numeral 110. As can be seen, orthodontic bracket 110 includesa body 112 and a lingual mounting pad 114 attached to the body. Themounting pad 114 has a lingual surface to be attached to a tooth. A pairof laterally spaced gingival tie wings 116 and a pair of laterallyspaced occlusal tie wings 118 extend from a labial surface of the body112. The gingival tie wings 116 and the occlusal tie wings 118 curvelingually. A horizontal crossbar 117 extends across the interwing region112′ of the body 112 and interconnects the occlusal tie wings 118. Aball hook 119 extends from one of the gingival tie wings 116.

The gingival surface 115 of the body in the interwing region 112′between the gingival tie wings 116 is convex and is generallysemi-elliptical. The labial surface of the body in the interwing region112 has a notch 150 formed in it. The gingival tie wings 116 arebevelled as indicated by reference numeral 121. An archwire slot 120extends mesiodistally across the body 112 and between the gingival andocclusal tie wings located at opposed mesial and distal sides of thebody and opens labially to receive an archwire 122. The occlusal wall ofthe archwire slot 120 is continuous and is constituted by the occlusaltie wings 118 and the crossbar 117. The occlusal wall of the archwireslot 120 has a notch formed in it to define two deflection surfaces 124and 126 respectively. Deflection surface 124 is constituted by a labialbevel while deflection surface 126 is constituted by a lingual bevel.

Looking at FIGS. 7 and 10, it can be seen that a curved groove 128 isformed in the gingival tie wings 116 and interwing region 112′ of thebody and extends mesiodistally. The groove 128 is spaced above thegingival surface of the body 112 and accommodates a pivot pin 130. Thepivot pin 130 is bonded to the gingival tie wings 116 by suitable meanssuch as brazing, soldering, welding or the like. A shutter 132resembling an inverted “T” in front elevation is pivotally mounted onthe pivot pin 130 in the interwing region 112′ and is movable between aclosed position where access to the archwire slot 120 is inhibited andan open position where access to the archwire slot 120 is permitted.

Referring now to FIGS. 11 a and 11 b, the shutter 132 is betterillustrated. As can be seen, the shutter 132 includes a lingually curvedupright stem 134 and a transverse arm 136 at the occlusal end of thestem. The edges of the shutter are curved at the intersection betweenthe stem 134 and transverse arm 136 to strengthen the shutter. The stem134 curves over itself at its gingival end and terminates in an openD-shaped cup 138 which partially surrounds the pivot pin 130 and isaccommodated in an undercut 39 formed in the interwing region 112′occlusally of the pivot pin to secure the shutter to the orthodonticbracket 110. A generally triangular aperture 140 is formed in the stem134 to receive a tool to facilitate pivoting of the shutter 132 from theclosed position to the open position. The occlusal portion of thetransverse arm 136 of the shutter is generally convex when viewed inprofile and is dimensioned to be accommodated in the archwire slot 120.The occlusal edge 142 of the transverse arm 136 is slightly concave.

The archwire slot 120 is designed to accommodate circular cross-sectionor rectangular cross-section archwires 122. When the archwire 122 ispositioned in the archwire slot and the shutter is closed, the lingualsurface of the shutter 132 contacts the archwire to urge it continuouslyagainst the body 112 (see FIG. 9 a). The deflection surface 126 inhibitsthe shutter 132 from being accidentally removed from the archwire slot120 when the archwire 122 applies a labially directed force to thearchwire. When it is desired to open the shutter 132, a tool is insertedinto the aperture 140 and is accommodated by the notch 150. The tool canthen be used to pivot the shutter with sufficient force so that theocclusal edge 142 of the transverse arm 136 passes over the deflectionsurface 126 and so that the end of the cup 138 rotates into the undercut139 allowing the shutter 132 to open.

During this pivotal movement of the shutter 132, the convex interwinggingival surface 115 of the body 112 and the flexing of the initiallycompressed shutter over the convex surface 115 as the shutter 132 pivotsaround the pivot pin 130 with the end of the shutter in the notch asshown in FIG. 9 b, maintains the shutter in an open condition. Theundercut 139 occlusally of the pivot pin 130 provides sufficientclearance for the shutter 132 to pivot freely in a rotary fashion.

Although the shutter 132 has been described as having a D-shaped cup 138to surround the pivot pin 130, the shutter can curl back around itselfto surround substantially the pivot pin 130 between the gingival tiewings. Also, although the pivot pin has been described as beingaccommodated in curved slots and bonded to the orthodontic bracket, itshould be apparent to those of skill in the art that the pivot pin maybe integrally formed with and extend between the gingival tie wings.

Although the gingival surface of the body in the interwing region hasbeen described as being semi-elliptical, it should be appreciated thatother surface configurations are suitable. Also, although the pivot pinhas been described as being accommodated in a groove extending acrossthe gingival tie wings and the body, the pivot pin may only extendbetween the gingival tie wings in the interwing region 112′ making thegingival tie wings more accessible. Also, although the shutter has beenshown as pivoting about a pivot pin extending between the gingival tiewings, the pivot pin may extend between the occlusal tie wings.

Referring now to FIGS. 12 to 15, yet another embodiment of anorthodontic bracket is shown and is generally indicated to by referencenumeral 220. As can be seen, orthodontic bracket 220 includes a body 222and a locking shutter 224. For illustrative purposes, the orthodonticbracket 220 is configured for a maxillary tooth but it can beappreciated that the orthodontic bracket 220 could be used on amandibular tooth.

Body 222 includes a lingual mounting pad 226 having a lingual toothattaching surface 228 adapted for direct attachment to a tooth or to apad that may be attached to a tooth. A pair of laterally spaced occlusaltie wings 234 and a pair of laterally spaced gingival tie wings 236project from a labial surface of the body 222. Each tie wing 234,236curves lingually to define an undercut 238 for receiving a ligature. Anarchwire slot 240 extends mesiodistally across the body 222 and betweenthe occlusal and gingival tie wings at opposed mesial and distal sidesof the body. The archwire slot 240 accommodates an archwire 242. Thearchwire slot 240 has a pair of opposed surfaces 244,246 at its mesialand distal ends. Inverted V-shaped deflection notches 248 are providedin the gingival tie wings 236 above the archwire slot. The deflectionnotches 248 are provided to receive a gingival edge 250 of the lockingshutter 224 in the closed position.

The locking shutter 224 extends between the occlusal and gingival tiewings at opposed mesial and distal sides of the body 222 and across thearchwire slot 240. The locking shutter 224 has a body 252 which iscranked as indicated at 254 to provide a pair of relatively inclinedportions 256,258. Occlusal edge 260 of the shutter body 252 is providedwith a recess 262 (as seen in FIGS. 12 and 14) so as to define a pair ofdownwardly projecting arms 264,266 that overlie respective ones of theocclusal tie wings 234 when the shutter 224 is in a closed position. Anaperture 267 is centrally positioned on the shutter 224 to accommodate atool to facilitate movement of the locking shutter.

The locking shutter 224 is retained on the orthodontic bracket 220 bymeans of an off-center pivot pin 268 that passes through an aperture(not shown) formed in the arm 264 and is secured to the occlusal tiewing 234. The shutter 224 is thus able to slide in a generallyocclusal-gingival plane about the pin 268 as indicated by arrow 269 inFIG. 14.

An indentation 272 is formed in the arm 266 and a corresponding dimple274 formed in the underlying occlusal tie wing 234. Arm 266 includes abuccally-extending return 276 that passes around the distal side of theocclusal tie wing 234 and has a retaining plate 278 that is receivedwithin a slot 280 formed in the side of the occlusal tie wing 234.

The indentation 272 cooperates with the dimple 274 to form a detentwhich inhibits pivotal movement of the shutter 224 about the pivot pin268 and retains the locking shutter 224 in the closed position. Theretaining plate 278 cooperates with the slot 280 and the shuttercooperates with the deflection notches 248 to inhibit labial movement ofthe locking shutter when in the closed position and an archwire appliesa labially directed force to the shutter so that the locking shutter 224retains the archwire 242 within the archwire slot 240.

To open the locking shutter 224, it is simply necessary to overcome thedetent provided by the indentation 272 and dimple 274 and rotate thelocking shutter 224 about the pivot pin 268. Access to the archwire slot240 is thus obtained. Similarly, to close the locking shutter 224, it issimply necessary to pivot the locking shutter about the pivot pin 268 sothat the gingival edge 250 engages the deflection notches 248 and theindentation 272 engages the dimple 274. The locking shutter 224 is thusheld securely and cooperates with the archwire 242 to apply therequisite forces to the archwire within the archwire slot.

An alternative embodiment of an orthodontic bracket is shown in FIGS. 16a to 17 b and is generally indicated to by reference numeral 220 a. Inthis embodiment, like components of the previous embodiment will beidentified with like reference numerals, with the suffix “a” added forclarity.

As can be seen, the locking shutter 224 a is pivotally secured to a boss290 that extends between the gingival tie wings 236 a by way ofcentrally positioned pivot pin 268 a. One edge 292 of the lockingshutter 224 a is arcuate giving the shutter 224 a a generallysemi-circular appearance. Deflection notches 248 a are formed in theocclusal tie wings 234 a adjacent the archwire slot 240 a. It will benoted that the labial surfaces of the occlusal tie wings 234 a arelabially protrusive so that the arcuate edge 292 of the locking shutter224 a is aligned with the deflection notches 248 a.

Dimples (not shown) are formed on each of the gingival tie wings 236 aand corresponding indentations 272 a are formed on the locking shutter224 a. The dimples and indentations 272 a cooperate when the lockingshutter 224 a is either in the open or closed positions to retain thelocking shutter in that position. An aperture 267 a is provided in theshutter to receive a tool and facilitate movement of the shutter 224 a.The locking shutter 224 a can be pivoted about pivot pin 268 a so as tobring the arcuate edge 292 into engagement with the notches 248 a asshown in FIGS. 17 a and 17 b by overcoming the detent provided by theindentations 272 a and dimples. In this position, the locking shutter224 a is effective to inhibit removal of an archwire from the archwireslot 240 a. The locking shutter 224 a can be readily moved to the openposition by rotating the locking shutter about the pivot pin 268 a toallow access to the archwire slot 240 a as shown in FIG. 16 a.

Another alternative arrangement of an orthodontic bracket 220′ is shownin FIGS. 18 to 20. In this embodiment, like reference numerals will beused to indicate like components of the embodiment of FIGS. 12 to 15with the suffix “′” added for clarity. In this embodiment, the lockingshutter 224′ is relieved and is generally C-shaped to provide a pair ofarms 264′ and 266′. Similar to the previous embodiment, the lockingshutter 224′ is pivotally secured to a boss 290′ extending between thegingival tie wings 236′ by way of a pivot pin 268′. A dimple 274′ isprovided on both gingival tie wings 236′. Indentations 272′ on the arms264′ and 266′ co-operate with the dimples 274′ with the detent formedbetween the indentations and dimples maintaining the locking shutter224′ in the open position. The notches 248′ define deflection surfacesto inhibit labial movement of the shutter 224′ and its removal from thearchwire slot 240′ when the shutter 224′ is in the closed position andan archwire applies a labially directed force to the shutter. In orderto move the shutter from the open to closed position, it is necessary toovercome the detent provided by the indentations 272′ and the dimples274′ and pivot the shutter 224′ about the pivot pin 268′.

In embodiments of the orthodontic brackets illustrated in FIGS. 12 to20, it will be observed that movement of the locking shutter betweenopen and closed positions is obtained by simple rotation of the lockingshutter about the pivot pin so that the locking shutter remains captiveto the body but at the same time is securely held in the closed and/oropen positions by the action of the detent formed between theindentations and dimples.

A further embodiment of an orthodontic bracket is shown in FIGS. 21 to24, in which like reference numerals will be used to denote likecomponents of the embodiment of FIGS. 12 to 15 with a suffix ‘c’ addedfor clarity. As can be seen, a circular track 500 is formed on themesial, distal, occlusal and gingival sides of the orthodontic bracket220 c. The circular track 500 passes through the occlusal and gingivaltie wings 234 c and 236 c respectively to intersect the archwire slot240 c. Bores 501 are formed in the circular tracks 500 in the mesial anddistal sides of the gingival tie wings 236 c slightly above the archwireslot 240 c. The archwire slot 240 cis offset occlusally so that thegingival tie wings 236 c are longer than the occlusal tie wings 234 c.

The track 500 receives a shutter in the form of a part circular clip 502having a circular protrusion 504 at one end. The clip 502 is slidable inthe track 500 but provides a friction grip against the track to inhibitunintentional movement. The circular protrusion 504 is accommodated byone of the bores 501 to hold the clip 502 in either the closed or openpositions.

The clip 502 may be rotated in the track 500 between an open position inwhich access to the archwire slot 240 c is available (see FIG. 24) and aclosed position in which access is inhibited (see FIGS. 22 and 23). Ascan best be seen in FIG. 22, the offset of the archwire slot 240 callows the clip 502 to overlie the archwire slot 240 c to retain anarchwire within the archwire slot. Rotation of the clip 502 throughapproximately 180 degrees moves the clip to the position shown in FIG.24 at which the archwire slot 240 c is open and access to the archwireis provided. The circular protrusion 504 facilitates rotation of theclip 502 between open and closed positions, with the friction betweenthe clip and the track 500 and the cooperating protrusion 504 and bore501 retaining the clip 502 in the desired position.

A still further embodiment of an orthodontic bracket 220 b is shown inFIGS. 25 to 27 in which like reference numerals will be used to denotelike components of the embodiment of FIGS. 12 to 15, with a suffix “b”added for clarity. As can be seen, the shutter 224 b is slidable withina slot 510 formed in each of the occlusal wings 234 b. A U-shaped strap512 is secured to the labial face of shutter 224 b and extends through aguide slot 514 and a washer 515 in the base of each of the slots 510. Acoil spring 516 is positioned in each slot beneath the shutter 224 b andsurrounds each arm 512 a of the strap 512. The arms 512 a are crankedslightly above the coil springs 516 toward the archwire slot 240 b asindicated to by reference numeral 518. The springs 516 bias the shutter224 b to a closed position in which the gingival edge 250 b of theshutter 224 b engages the notches 248 b.

The labial surface of the shutter 224 b carries a wedge 520 thatcooperates with a complementary recess 522 formed in the slots. Thewedge 520 retains the shutter 224 b in the open position and may bereleased by application of a force to the bight 512 b of the strap 512to release the shutter 224 b under the action of the springs 516. Theshutter 224 b is thus retained in the closed position to resist labialmovement of an archwire 242 b in the archwire slot 240 b. The springloaded shutter 224 b may also be applied in a similar manner to twosingle orthodontic brackets or a 3 wing orthodontic bracket.

A still further embodiment of an orthodontic bracket 220 d is shown inFIGS. 28 to 31 where like reference numerals will be used to indicatelike components of the embodiment illustrated in FIGS. 12 to 15 with thesuffix “d” added for clarity. In this embodiment, grooves 530 are formedin the mesial and distal sides of the body 222 d. Each groove 530extends through the gingival and occlusal tie wings 236 d and 234 d. Thegrooves 530 terminate in blind bores 532 in the gingival tie wings 236d. Blind bores 534 are also formed in the grooves 530 in the occlusaltie wings 236 d adjacent the archwire slot 240 d (see FIG. 31). Theocclusal surfaces of the occlusal tie wings 236 d are undercut toprovide a lateral groove 536 that extends mesiodistally between theocclusal tie wings.

A shutter 224 d in the form of a generally U-shaped clip 538 is formedwith a pair of outer arms 540 interconnected by a lateral bight 542. Theends of the arms 540 are formed with inwardly-directed projections 544for receipt within the bores 532 or 534.

A support arm 546 is secured to the lateral bight 542 and is jogged toprovide a horizontal arm 546 a between a pair of vertical arms 546 b and546 c respectively. One of the vertical arms 546 c is received within avertical slot 548 in the body 220 d and maintains alignment of the clip538 as it is moved between the open and closed positions. The slot 548is located in the interwing region of the body 222 d to provide uniformsupport.

The clip 538 is assembled on the orthodontic bracket 220 d so that thearms 540 are received within the respective grooves 530. The projections544 are received within the blind bores 534 so that the archwire slot240 d is open for receipt of an archwire as shown in FIG. 30 a. With thearchwire 242 d inserted into the archwire slot 240 a as shown in FIG. 30b, the clip 538 may be advanced along the grooves 530 until theprojections 544 are received within the blind bores 532. In thisposition, the lateral bight 542 is received within the lateral groove536 to provide further security for the clip 538. The vertical arm 546 cand slot 548 serve to guide and align the clip 538 during sliding motionto facilitate the relative movement between the clip and the orthodonticbracket 220 d.

A further embodiment of an orthodontic bracket 220 e is shown in FIGS.32 to 36. In this embodiment like reference numerals will be used todenote like components of the embodiment of FIGS. 12 to 15 with a suffix“e” added for clarity. In the embodiment of FIGS. 32 to 36, grooves 560are formed in the occlusal tie wings 234 e only. The shutter 224 eincludes side flanges 562 that have inwardly directed protrusions 564 toengage the grooves 560. The shutter 224 e has a pair of linguallyangulated occlusal arms 264 e and 266 e and a centrally positionedgingival arm 566 defined partly by a pair of slits 568 in the shutter224 e (best seen in FIG. 36). The gingival arm 566 is recurved in alabial direction as indicated by reference numeral 569 and is resilientto engage the labial notches 248 e at the mesial and distal ends of thearchwire slot 240 e and inhibit labial movement of shutter 224 e when anarchwire applies a labially directed force to the shutter. Protrusions570 are provided on the sides of the shutter 224 e to form a handle andfacilitate sliding movement of the shutter 224 e between the open andclosed positions. Again therefore, a sliding shutter is provided on theorthodontic bracket 220 e to retain an archwire in the archwire slot 240e.

In a further embodiment shown in FIG. 37, a known orthodontic bracket220 f sold under the trade name “SPEED” is shown and includes a pair ofocclusal tie wings 234 f below a shutter 224 f and a pair of gingivaltie wings above the shutter 224 f to provide a twin orthodontic bracket.The gingival tie wings can be spaced further apart to make theorthodontic bracket more symmetrical.

Referring now to FIGS. 38 to 41, still yet another embodiment of anorthodontic bracket is shown. In this embodiment, like referencenumerals will be used to denote like components of the embodiment ofFIGS. 12 to 15 with a “1000” added for clarity. As can be seen, theorthodontic bracket 1220 is similar to one of the orthodontic bracketsdisclosed in Applicant's U.S. Pat. No. 5,474,445 issued on Dec. 12,1995, the contents of which are incorporated herein by reference. Inthis embodiment, a projection 1001 is formed on the gingival surface1003 of the body 1222 in the interwing region. The shutter 1224generally resembles a cruciform and has a gingival arm 1005 with aninverted doghouse shaped aperture 1267 in it to accommodate theprojection 1001 and retain the shutter 1224 in the closed position. Theshape of the aperture 1267 also permits a tool to enter the aperture sothat a labially directed force can be applied to the shutter 1224 usingthe tool to release the shutter 1224 from the projection 1001. Themesial and distal arms 1007 and 1009 respectively of the shutter 1224curve lingually into the archwire slot 1240. The arms 1007 and 1009 areresilient and are somewhat flattened when contacting a full dimensionrectangular archwire 1242 accommodated in the archwire slot 1240 toapply a bias to move the archwire 1242 into the base of the archwireslot. In this way, a continuous rotation action and torque is applied tothe archwire whether round or rectangular (even where that archwire isof relatively small cross-sectional dimension) to apply a continuousforce to the tooth through the orthodontic bracket 1220. The occlusalarm 1011 of the shutter 1224 curves labially to define a single loopwhich surrounds a pivot pin 1013 to secure the shutter 1224 to theorthodontic bracket 1220 and to provide a shutter with a continuoussmooth lingual surface.

FIG. 41 a shows an alternative embodiment of the shutter and pivot pindesign. In this embodiment, a dimple 1013 a is formed in the pivot pin1013 and an indentation 1224 a is provided in the shutter 1224. Theindentation 1224 a and dimple 1013 a cooperate when the shutter is in aclosed position to provide further security to inhibit accidentalopening of the shutter.

A similar arrangement of an orthodontic bracket 2220 to that describedabove is shown in FIGS. 42 to 45. In this embodiment, like referencenumerals will be used to denote like components of the embodiment ofFIGS. 12 to 15 with a “2000” added for clarity. As can be seen, theorthodontic bracket 2220 also has a shutter 2224 generally resembling acruciform. The gingival arm 2005 of the shutter 2224 has a doghouseshaped aperture 2267 in it to accommodate a projection 2001 and retainthe shutter 2224 in the closed position. Unlike the previous embodiment,the mesial and distal arms 2007 and 2009 on the shutter 2224 arerelatively rigid. A spring member in the form of a ribbon 700 is locatedon the lingual surface of the shutter 2224 and extends mesiodistally.The ribbon 700 is configured to provide a pair of convex linguallyextending formations 702 that are aligned with the occlusal and gingivaltie wings at opposed mesial and distal sides of the body 2222 and thusbear against an archwire 2242 located in the archwire slot 2240. Thecentral portion 704 of the ribbon 700 is secured to the shutter 2224with the lateral extremities 706 of the ribbon being free to slidehorizontally over the lingual surface of the shutter 2224 and therebyallow flexure of the formations 702. In this manner, differentthicknesses of archwires 2242 can be accommodated by the orthodonticbracket 2220 while still ensuring that a continuous force is applied tothe tooth through the orthodontic bracket.

FIG. 45 a illustrates an alternative embodiment of a ribbon 700′ for usewith the orthodontic bracket 2220. In this embodiment, the ribbon 700′is secured to the lingual surface of the occlusal arm 2011 of theshutter 2224 adjacent one of its ends and extends in a gingival-occlusaldirection. The other end 706′ of the ribbon 700′ is free to sliderelative to the lingual surface of the shutter 2224 as indicated by thedotted line 710. The tong 700′ presents a convex surface 702′ whichenters the archwire slot 2240 when the shutter is in a closed positionto bias the archwire 2242 into the archwire slot.

FIGS. 46 and 47 illustrate alternative embodiments of orthodonticbrackets 1220′ similar to that illustrate in FIGS. 38 to 41. In theseembodiments, like reference numerals will be used to indicate likecomponents of the embodiment of FIGS. 38 to 41 with a “′” added forclarity. In the embodiment of FIG. 46, the shutter 1224′ has shortmesial and distal arms 1007′ and 1009′ which curve lingually into thearchwire slot 1240′ to apply a bias to an archwire 1242′ accommodated bythe archwire slot 1240′. In the embodiment of FIG. 47, the shutter 1224′has longer mesial and distal arms 1007′ and 1009′ which curve linguallyinto the archwire slot 1240′ to apply a bias to an archwire 1242′accommodated by the archwire slot 1240′.

Referring now to FIGS. 48 to 52, still yet another embodiment of anorthodontic bracket 3220 d is shown similar to that shown in FIGS. 28 to31. In this embodiment, like reference numerals will be used to denotelike components of the embodiment of FIGS. 28 to 31 with a “3000” addedfor clarity. As can be seen, the orthodontic bracket 3220 d can bemodified to provide a continuous seating action bias to an archwireaccommodated in the archwire slot. In this arrangement, a spring memberin the form of a resilient shim 720 is attached to the vertical arm 3546b of the support arm 3546. The shim 720 thus projects gingivally fromthe labial edge of the horizontal arm 3546 a so as to be spaced from thelingual vertical arm 3546 c. The shim 720 has a jog directed linguallytoward the archwire slot 3240 d and presents a generally convex surface722 towards the archwire slot 3240 d. The gingival edge 724 of the shim720 recurves labially.

As the arms 3540 slide within the slots 3530 to the move the clip 3538to a closed position as shown in FIG. 49, the convex surface 722 of theshim 720 engages the archwire 3242 d and provides a continuous biasingaction against the archwire (best seen in FIG. 50). As may be seen inFIG. 51, the resilience of the shim 720 allows the orthodontic bracket3220 d to accommodate different sizes and configurations of archwires3242 d while maintaining a continuous action against the archwire.

Referring now to FIGS. 53 to 55, still yet another embodiment of anorthodontic bracket 4220 is shown similar to that shown in FIGS. 12 to15. In this embodiment, like reference numerals will be used to denotelike components of the embodiment of FIGS. 12 to 15 with a “4000” addedfor clarity. As can be seen, the orthodontic bracket 4220 can bemodified to provide a continuous bias to an archwire accommodated in thearchwire slot. In this embodiment, a spring member in the form of aresilient shim 730 is secured to the lingual surface of the shutter 4224adjacent the interwing region of the body 4220. The shim 730 isintegrally formed with the shutter 4224 and is folded lingually aboutthe occlusal edge 4260 of the shutter between the arms 4264 and 4266respectively. The shim 730 is curved lingually to present a generallyconvex surface 732 spaced from the shutter 4224 and its end 734 recurvedto form a smooth lip engaged with the lingual face of the shutter 4224.The end 734 of the shim 730 is free to slide relative to the shutter4224 when the convex surface 731 is flattened due to contact with anarchwire 4242 in the archwire slot 4240, The shim 730 is thus able tocontinuously exert a corrective force upon different configurations ofarchwires 4242 within the archwire slot 4240 when the shutter 4224 is inthe closed position.

Referring now to FIGS. 56 to 58, still yet another embodiment of anorthodontic bracket 5220 b is shown similar to that shown in FIGS. 25 to27. In this embodiment, like reference numerals will be used to denotelike components of the embodiment of FIGS. 25 to 27 with a “5000” addedfor clarity. As can be seen, the orthodontic bracket 5220 b can bemodified to provide a continuous bias to an archwire accommodated in thearchwire slot. In the arrangement shown, a spring member in the form ofa resilient shim 740 is formed on the lingual face of the shutter 5224 bin the archwire slot 5240 b. The shim 740 is formed with a convexlingual surface 742 that engages an archwire 5242 b when the shutter5224 b is in the closed position. The shim 740 is secured to the shutter5224 b adjacent its occlusal end only and therefore, the gingival end744 of the shim 740 is free to slide relative to the shutter 5224 b. Inthis manner, the shim 740 may flex to accommodate different sizes andshapes of archwires 5242 b accommodated in the archwire slot 5240 b toprovide a continuous action on the archwire wire.

Referring now to FIGS. 59 to 62, still yet another embodiment of anorthodontic bracket 6220 e is shown similar to that shown in FIGS. 32 to36. In this embodiment, like reference numerals will be used to denotelike components of the embodiment of FIGS. 32 to 36 with a “6000” addedfor clarity. As can be seen, the orthodontic bracket 6220 e can bemodified to provide a continuous bias to an archwire accommodated in thearchwire slot. In the arrangement shown, a spring member in the form ofa shim 750 is secured to the lingual surface of the shutter 6224 e andpresents a convex surface 752 toward the archwire slot 6240 e to engagean archwire 6242 b in the same manner as described above to provide acontinuous action on the archwire wire. The gingival edge 754 of theshim is free to slide relative to the lingual surface of the shutter6224 e.

A continuously acting orthodontic bracket may also be provided withself-locking labial brackets such as those shown in U.S. Pat. No.5,094,614 to Wildman, the contents of which are incorporated herein byreference. As shown in FIGS. 63 to 71, the orthodontic bracket 7220 hasa pair of wings 7242 with an archwire slot 7240 to receive an archwire7242.

A shutter 7224 is located between the gingival and occlusal tie wingslocated at opposed mesial and distal sides of the body 7222 and includesa central body portion 7322 encompassed by a locking spring 7324. Themesial and distal edges of the shutter body 7322 are received withingrooves 7326 so that the shutter 7224 may slide between open and closedpositions. The grooves 7326 have undercuts 7328 that terminate at steps7330 in the occlusal and gingival tie wings 7234 and 7236 respectively.The steps 7330 receive one end of a spring 7324. The opposite ends areformed as an occlusal tail. A spring member in the form of a resilientshim 760 is secured to the tail 7332 so as to be spaced from theretaining spring 7324. A lingual step 7235 accommodates the shim 760from a lingual aspect. The shim 760 thus engages an archwire 7242 in thearchwire slot 7240 when the shutter 7224 is in the closed position in aresilient manner to provide a continuous biasing action against thearchwire as shown in FIG. 6 b. The step 7330 retains the shutter 7224 inthe closed position with the resilient shim 760 biased against thearchwire 7242. As shown in FIG. 67, the shim 760 may be secured to thetail 7332 as a separate structure. Alternatively, as shown in FIG. 69,the shim 760 may be formed on the tail 7332 of a liner layer 7334 thatencompasses the body 7322. The spring 7324 extends over the upper edgeof the body 7322 and terminates above the upper edge of the shim 760.The shim 760 is thus free to flex to accommodate different sizes anddispositions of archwires while providing a continuous action on thearchwire.

Similarly, as shown in FIG. 70, the shim 760 may be secured at its upperedge to the spring 7324 with the lower edge free of the tong to sliderelative to the shutter upon flexure of the shim 760.

An alternative arrangement for the shim 760 is shown in FIGS. 72 and 73.In this embodiment, the resilient shim 760 is defined in the lingualaspect of the outer layer of the spring 7324. Three sides of the shim760 are defined by slots 764 cut into the lingual aspect of the outerlayer of the spring to define the periphery of the shim 760. Theresultant shim defines an inwardly convex surface 762 that resilientlyengages the archwire. Naturally, such a shim 760 may be formedintegrally with the springs 7324 to facilitate manufacture.

A further modification of an existing orthodontic bracket 7220′ is shownin FIGS. 74 to 78 in which the orthodontic bracket known as the Damonbracket and shown in U.S. Pat. No. 5,439,378, the contents of which areincorporated herein by reference, is modified to provide a spring memberin the form of a resilient shim 770 on the lingual surface of theshutter 7224′. Shutter 7224′ may be extended occlusally to accommodatethe shim 770 which in this embodiment is formed by folding a continuousextension of the shutter 7224′ back upon itself. The shim 770 presents aconvex surface 772 which enters the archwire slot 7240′ when the shutter7224′ is in a closed position. One end 744 of shim 770 is free to sliderelative to the shutter 7224′. In this manner, the shim 770 may flex toaccommodate different sizes and shapes of archwires 7242′ accommodatedin the archwire slot 7240′ to provide a continuous action on thearchwire.

As those of skill in the art will appreciate, in the embodimentsillustrated in FIGS. 38 to 78, the spring member may be formed as aseparate member and attached to the shutter adjacent either its gingivalor occlusal ends in a manner so that it extends into the archwire slotto bias the archwire. Alternatively, the spring member may be integrallyformed with the shutter by a folding portion of the shutter about anedge. If the spring member is to be integrally formed with the shutter,a continuous extension of the shutter is typically folded about either agingival or occlusal edge of the shutter and is configured so that itextends into the archwire slot to bias the archwire.

Referring now to FIGS. 79 to 82, still yet another embodiment of anorthodontic bracket 8220 is shown similar to that shown in FIGS. 16 a to17 a. In this embodiment, like reference numerals will be used to denotelike components of the embodiment of FIGS. 16 a to 17 b with a “8000”added for clarity. As can be seen, the resilient locking shutter 8224 ais pivotally secured to a boss 8290 that extends between the gingivaltie wings 8236 a by way of a centrally located pivot pin 8268 a. Theboss 8290 is located on a lingually bevelled labial surface of the body822 a. Thus, the shutter 8224 a is inclined. One edge 8292 of thelocking shutter 8224 a is arcuate to give the shutter a generallysemi-circular appearance. Deflection notches 8248 a are formed in thearchwire slot 8240 a adjacent the occlusal tie wings 8234 a.

Dimples (not shown) are formed on each of the gingival tie wings 8236 aand corresponding indentations 8272 a are formed on the locking shutter8224 a. The dimples and indentations 8272 a cooperate when the lockingshutter 8224 a is either in the open or closed positions to retain thelocking shutter in that position. An aperture 8267 a is provided in theshutter 8224 a to receive a tool and facilitate movement of the shutter8224 a. The locking shutter 8224 a can be pivoted about pivot pin 8268 aso as to bring the shutter 8224 a into engagement with the archwire 8242a in the archwire slot 8240a as shown in FIG. 81 by overcoming thedetent provided by the indentations 8272 a and dimples. In thisposition, the locking shutter 8224 a is effective to inhibit removal ofan archwire 8242 from the archwire slot 8240 a and provides a continuousaction on the archwire. The locking shutter 8224 a can be readily movedto the open position by rotating the locking shutter about the pivot pin8268 a to allow access to the archwire slot 8240 a. As can be seen inFIG. 82, when a larger archwire 8242 is accommodated by the archwireslot 8240 a, the shutter 8224 a flexes to accommodate the archwire yetprovide a continuous action on the archwire. The deflection notches 8248a and the angulated orientation of the shutter 8224 a inhibit theshutter 8224 a from moving labially out of the archwire slot 8240 a.

Another embodiment of an orthodontic bracket 9220 utilizing analternative shutter structure is shown in FIGS. 83 to 87. In thisembodiment, like reference numerals will be used to denote likecomponents of the embodiment of FIGS. 12 to 15 with a suffix ‘9000’added for clarity. As shown in FIGS. 83 to 87, the shutter 9224 ispivotal and is formed from a wire 9001 bent into a generally cruciformoutline. The wire 9001 has opposite ends that are turned over to provideoppositely-directed tails 9003 and 9005. The tails 9003, 9005 extendparallel to a common axis but are offset from one another.

Each of the tails 9003, 9005 is received in a respective bore 9007formed in each of the occlusal tie wings 9234. The tails 9003, 9005 arefree to rotate within the respective bores to permit pivotal movement ofthe shutter 9224.

The wire 9001 defines a pair of oppositely-directed arms 9009, 9011which extend across the archwire slot 9240. A horizontal recess 9013 isformed in each of the gingival tie wings 9236 adjacent the archwire slot9240 to provide an abutment surface to limit pivotal movement of theshutter 9224 towards the archwire slot 9240.

The wire 9001 between the arms 9009, 9011 is formed into arearwardly-projecting hook 9015 as can best be seen in FIG. 84 and isreceived within groove 9017. An extension 9019 is formed on the gingivalsurface of the body 9222 and passes through the hook 9015 when theshutter 9224 is in a closed position to provide a frictional fit betweenthe hook 9015 and body 9222 and retain the shutter in the closedposition.

As shown in FIG. 84, the hook 9015 retains the shutter 9224 against thearchwire 9242 and inhibits relative movement between the archwire andthe body 9222 of the orthodontic bracket 9220. To release the archwire9242, the shutter 9224 is caused to pivot about the offset tails9003,9005 to release the hook 9015 from the extension 9109. As theshutter 9224 is rotated, the eccentricity of the axes of rotation of thetails 9003, 9005 causes a torsional resistance due to flexure of thewire 9001 tending to return the shutter 9224 to the closed position.This movement is opposed until such time as the shutter 9224 goes overcenter, at which point the shutter 9224 becomes biased to the openposition as shown in FIG. 87. In this way, the shutter 9224 isresiliently biased toward the body 9222 as it is moved towards theclosed position but remains in a stable, open position at other times.

A further embodiment of an orthodontic bracket 9220′ utilizing a wirefor a shutter 9224′ is shown in FIGS. 88 and 89, where like componentsof the previous embodiment will be described using like referencenumerals with a suffix “′” added for clarity. In this embodiment, theshutter 9224′ is formed from a wire 9001′ having oppositely directedtails 9003′, 9005′. Each of the tails 9003′, 9005′ is pivotally receivedwithin bores 9007′ which are aligned on a common axis to allow freepivotal movement of the shutter 9224′. The bores may also be offset asshown in FIG. 83.

The wire 9001′ between the arms 9009′, 9011′ is formed as an elongateU-shaped projection 9020 and is received within a locking clip 9022. Ascan best be seen in FIG. 89, locking clip 9022 is generally U-shapedwith serpentine limbs terminating in outwardly-flared ends 9024. Theprojection 9020 may be received between the flared ends 9024 to forcethe limbs apart but is then resiliently retained between the limbs in astable manner. The locking clip 9022 may alternatively have a generallycircular section as shown in FIG. 90 but it is believed the clip 9022shown in FIG. 89 facilitates insertion of the projection 9020. Again,the shutter 9224′ retains the archwire 9242′ within the archwire slot9240′ when the locking clip 9022 retains the shutter 9224′ in a closedposition.

Referring now to FIGS. 91 a and 91 b, orthodontic tools 900 are shownwhich are suitable to open and close the shutters of the orthodonticbrackets. As can be seen, each orthodontic tool 900 comprises a centralbody portion 902, a nose-shaped portion 904 at one end of the bodyportion for opening the shutter and a generally square corrugatedfork-shaped portion 906 at the opposite end of the body portion 902 forgripping and guiding archwires lingually into the archwire slots tofacilitate closure of the shutters. The fork-shaped portion straddlesthe outside of the bracket mesially and distally. In use, thenose-shaped portion 904 is inserted into the aperture in the shutter anda force is applied to the shutter using the tool 900 to move the shutterin the desired manned. In the embodiment of FIG. 91 a, the fork-shapedportion 906 is aligned with the body portion 902 while in the embodimentof FIG. 91 b, the fork-shaped portion 906 is at right angles to the bodyportion. Other angles between the body portion 902 and the fork-shapedportion 906 are of course suitable. Also, the shape of the nose-shapedportion 904 can vary to complement the aperture in the shutter.

Referring now to FIGS. 92 a to 92 c still yet another embodiment of anorthodontic bracket is shown and is generally indicated to by referencenumeral 10010. The orthodontic bracket 10010 includes a body 10012 and alingual mounting pad 10014 attached to the body. The mounting pad 10014has a lingual surface 10015 to be attached to a tooth. A pair ofgingival tie wings 10016 and a pair of occlusal tie wings 10018 extendfrom a labial surface of the body 10012. The gingival tie wings 10016and the occlusal tie wings 10018 curve lingually. Both the gingival tiewings 10016 and the occlusal tie wings 10018 at opposed mesial anddistal sides of the body are separated by an interwing region 10019 ofthe body 10012. An archwire slot 10020 extends mesiodistally across thebody between the gingival and occlusal tie wings at opposed mesial anddistal sides of the body and opens labially to receive an archwire10022. The archwire slot 10020 is interrupted mesiodistally in theinterwing region 10019. A locking shutter 10024 is accommodated byrecesses 10026 in the gingival and occlusal tie wings and is moveablebetween a closed position where the archwire is locked into the archwireslot and access to and the release of the archwire slot 10020 isinhibited, and an open position where access to the archwire slot ispermitted.

Within the archwire slot 10020 is a slot activator in the form of agenerally rectangular, resilient spring member 10032 formed of suitablematerial such as for example Nickel-Titanium or spring stainless steel.The spring member 10032 extends mesiodistally along the archwire slot.The spring member 10032 has a central portion 10034 secured to thelingual wall of the archwire slot 10020 such as for example by way of aweld 10036 or a sleeve (not shown). Opposed ends of the spring member10032 curve labially towards the locking shutter 10024 to defineprotrusive mesial and distal wings 10038 and 10040. The mesial anddistal wings 10038 and 10040 of the spring member 10032 extend into thearchwire slot 10020 starting from the lingual wall of the archwire slota distance equal to approximately one third to one half of the depth ofthe archwire slot. The archwire slot 10020 formed in the body 10012 ismildly deeper than in conventional orthodontic brackets to accommodatethe thickness of the central portion 10034 of the spring member 10034.

In use, when an archwire 10022 is placed into the archwire slot 10020and the locking shutter 10024 is closed, the mesial and distal wings10038 and 10040 of the spring member 10032 contact the archwire 10022 tobias it towards the locking shutter 10024. As shown in FIGS. 92 b and 92c, when a small round archwire is used, the archwire 10022 is biased bythe spring member 10032 to control and seat the archwire towards thelocking shutter. During initial treatment, biasing of the archwire 10022in this manner provides initial tooth movements to produce accuraterotation corrections and in-out (horizontal plane) movements of teeth.During the middle of treatment, biasing of the archwire in this mannercontrols and supports bodily tooth movement preventing rotation of teethas they slide along a straight archwire by a pull force.

FIG. 92 d shows the orthodontic bracket 10010 accommodating a largerectangular archwire 10022 in the archwire slot 10020 which is used atthe end of treatment. In this case, the labially curved mesial anddistal wings 10038 and 10040 of the spring member 10032 are partiallyflattened by the archwire but continue to act on the archwire to bias ittowards the locking shutter 10024. Biasing the archwire 10022 in thismanner applies a labial force on the archwire against the lockingshutter 10024 to produce desired root torque in the tooth root andcrown.

Referring now to FIG. 93, still yet another embodiment of an orthodonticbracket is shown and is generally indicated to by reference numeral10110. In this embodiment, the slot activator is in the form of agenerally rectangular, convex resilient spring member 10132 formed ofspring stainless steel. The mesial and distal ends 10138 and 10140 ofthe spring member 10132 are flattened. Distal end 10140 of the springmember 10132 is secured to the lingual wall of the archwire slot 10120by way of a weld 10136 while the mesial end 10138 of the spring member10132 is free.

Although the distal end of the spring member 10132 is shown attached tothe body, it should be apparent to those of skill in the art that themesial end of the spring member 10132 may be secured to the body withthe distal end of the spring member 10132 being free. The length of thespring member 10132 is less than the length of the archwire slot 10120so that the free end of the spring member remains in the archwire slotwhen the spring member 10132 is partially flattened by a largerectangular archwire accommodated by the archwire slot.

The orthodontic bracket 10110 functions in a similar manner to theprevious embodiment. When a small round archwire is placed in thearchwire slot 10120 and the locking shutter (not shown) is closed, theconvex spring member 10132 biases the archwire 10122 towards the lockingshutter. When a large rectangular archwire 10122 is placed in thearchwire slot 10120, the spring member is only partially flattened andbiases the archwire towards the locking shutter.

Referring now to FIG. 94, still yet another embodiment of an orthodonticbracket is shown and is generally indicated to by reference numeral10210. In this embodiment, the slot activator is similar to that shownin the previous embodiment except that the spring member 10232 isoriented to extend occlusiogingivally in the interwing region 10219between the occlusal and gingival tie wings 10218 and 10216respectively. The occlusal end 10250 of the spring member 10232 issecured to the body by way of a weld 10236 while the gingival end 10252of the spring member 10232 is free. Although the occlusal end of thespring member 10232 is shown attached to the body, it should be apparentto those of skill in the art that the gingival end of the spring member10232 may be secured to the body with the occlusal end of the springmember being free.

FIG. 95 illustrates still yet another embodiment of an orthodonticbracket in accordance with the present invention. In this embodiment,the orthodontic bracket 10310 includes magnetized bars 10360 and 10362inserted into recesses 10364 formed in the lingual and gingival walls ofthe body 10312 defining the archwire slot 10320. The magnetized bars10360 and 10362 are oriented so that they present a magnetic field ofthe same polarity into the archwire slot 10320. The archwire 10322 to beaccommodated in the archwire slot is magnetized to the same polarity asthe magnetized bars 10360 and 10362 so that the archwire is repelled andbiased labially and occlusally in the archwire slot towards the lockingshutter 10324. If desired, the locking shutter can be magnetized to theopposite polarity as the archwire to attract it.

Referring now to FIGS. 96 a and 96 b, still yet another embodiment of anorthodontic bracket is shown and is generally indicated to by referencenumeral 10410. In this embodiment, the slot activator 10430 is in theform of a pair of spring loaded pistons 10470 extending into thearchwire slot 10420 and positioned at opposed mesial and distal ends ofthe archwire slot between the occlusal and gingival tie wings 10418 and10416 respectively. Each spring loaded piston 10470 includes a labiallyextending piston head 10472 to contact an archwire 10422 in the archwireslot. A coil spring 10474 is accommodated in a bore 10476 formed throughthe body 10412 and acts between the mounting pad 10414 and the back ofthe piston head 10472 to bias the piston head in a direction towards thelocking shutter 10424. The piston heads 10472 are dimensioned to fillapproximately one-third to one-half of the vertical dimension of thearchwire slot to inhibit the archwire from sliding up or down and behindthe piston head.

Referring now to FIGS. 97 a to 97 c still yet another embodiment of anorthodontic bracket is shown and is generally indicated to by referencenumeral 10510. In this embodiment, the slot activator is in the form ofa generally rectangular, stainless steel spring member 10532 and islocated external to the archwire slot 10520. The spring member 10532includes a central portion 10534 which runs mesiodistally along thelingual wall of the body 10512 and is trapped between the body 10512 andthe lingual mounting pad 10514. Labially extending wings 10538 and 10540are provided at the mesial and distal ends of the spring member 10532and contact an archwire 10522 extending along the archwire slot 10520exterior to the archwire slot near the mesial and distal sides of thebody 10512. Thus, the spring member 10532 in this embodiment is externalto the archwire slot 10520 but still biases an archwire 10522 in thearchwire slot labially towards the locking shutter 10524. The labialextending wings 10538 and 10540 contact the archwire at a lateral anglegreater than 90° to facilitate flattening of the labial wings when alarge rectangular archwire is accommodated by the archwire slot 10520.

In this embodiment, the locking shutter 10524 includes a single loopadjacent one end to surround a pivot pin 10580 extending between theocclusal tie wings 10518. A hole 10582 is provided in the lockingshutter 10524 and co-operates with a pair of spaced projections 10584extending upwardly from the gingival surface of the body in theinterwing region of the orthodontic bracket. Each projection 10584includes a head 10586 and an undercut stem 10588 supporting the headabove the gingival surface of the body. The projections 10584 are spaceda distance slightly greater than the diameter of the hole 10582 so thatthe heads 10586 must be compressed towards one another to fit into thehole. The undercut stems 10588 allow the projections 10584 to snap backto their original positions once the heads have passed through the hole10582 thereby to lock the shutter 10524 in place in a closed position.

Referring now to FIGS. 98 a and 98 b, still yet another embodiment of anorthodontic bracket is shown and is generally indicated to by referencenumeral 10610. Orthodontic bracket 10610 is similar to that shown inFIGS. 92 a to 92 d except that the ends 10638 and 10640 of the springmember 10632 extend mesiodistally beyond the archwire slot 10620 andcontact the archwire 10622 exterior to the archwire slot but near themesial and distal sides of the body 10612.

FIGS. 98 c and 98 d illustrate another embodiment of an orthodonticbracket 10610′ similar to that shown in FIGS. 98 a and 98 b. In thisembodiment, one of the gingival tie wings 10616′ has a pair of grooves10625 formed in its opposed sides to obviate the need for an upwardlyextending hook on the tie wing.

FIGS. 99 a and 99 b show still yet another embodiment of an orthodonticbracket 10710. As can be seen, orthodontic bracket 10710 is similar tothat illustrated in FIG. 94 and includes an occlusiogingivally extendingslot activator positioned in the interwing region 10719 between theocclusal and gingival tie wings 10718 and 10716 respectively. The slotactivator is in the form of a curved spring member 10732. The springmember passes through a vertical slot 10741 formed in the body 10712 ofthe orthodontic bracket lingual to the archwire slot 10720 and whichopens up at the archwire slot. The occlusal end 10738 of the springmember 10732 is secured to the occlusal surface of the body such as forexample by a weld. The gingival end 10740 of the spring member 10732 isfree allowing the free end of the spring member to move when the springmember is flattened by an archwire 10722 in the archwire slot 10720 asindicated by the dotted lines 10745.

Referring now to FIGS. 100 a to 100 c still yet another embodiment of anorthodontic bracket is shown and is generally indicated to by referencenumeral 10810. Orthodontic bracket 10810 is similar to that shown inFIGS. 97 a to 97 c and includes a pivotal locking shutter 10824 having asingle loop at one end surrounding a pivot pin 10880 extending betweenthe occlusal tie wings 10818. The gingival end of the locking shuttercurves occlusally and snaps over a bulbous lip 10875 formed on thegingival surface of the body 10812 in the interwing region 10819 tomaintain the locking shutter in the closed condition. An opening 10877is provided through the locking shutter to accommodate a tool tofacilitate opening of the locking shutter. A marker 10879 is alsoprovided on the labial surface of the locking shutter below the opening.The marker identifies the center of the archwire slot 10820 tofacilitate proper placement of the orthodontic bracket on the center ofthe long axis of a tooth. The marker 10879 can of course be provided onthe locking shutter 10824 at any suitable location so as to identify theposition of the archwire slot. In this particular embodiment, the markeris in the form of a coloured circle on the labial surface of the lockingshutter. It should however be apparent that the marker can be of anyother suitable form such as for example an embossed or depressed regionor a laser marking on the locking shutter.

The slot activator in the embodiment is in the form of a pair of springmembers 10832. The spring members extend labially along the mesial anddistal sides of the body 10812 and contact an archwire 10822accommodated by the archwire slot 10820 exterior to the archwire slotbut near the mesial and distal sides of the body 10812. The springmembers 10832 are secured to the body by welds and contact the archwireat a lateral angle greater than 90° to facilitate flattening of thespring members 10832 when a large rectangular archwire is accommodatedby the archwire slot.

In the embodiment illustrated in FIG. 100 d, the configuration of thelocking shutter 10824′ and the lip 10875′ on the gingival surface of thebody 10812′ in the interwing region is modified slightly from that shownin FIGS. 100 a to 100 c. In this particular arrangement, the gingivalend of the locking shutter 10824′ and the lip 10875′ are configured aswedges which snap over one another to maintain the locking shutter inthe closed condition. The opening 10877′ in the locking shutter 10824′accommodates a tool to facilitate pivoting of the locking shutter overthe lip 10875 to allow the locking shutter to be pivoted to the opencondition.

Referring now to FIGS. 101 a to 101 d still yet another embodiment of anorthodontic bracket is shown and is generally indicated to by referencenumeral 10910. In this embodiment, the orthodontic bracket includes aslot activator in the form of a spring member 10932 similar to thatshown in FIGS. 98 a and 98 b. The locking shutter 10924 is however of adifferent configuration. In particular, the locking shutter 10924 isgenerally T-shaped in front plan and is constituted by a pair of shutterelements 10981 generally overlying one another and retained in proximityby flaps 10983 integrally formed on one of the shutter elements andwhich have been folded over the other of the shutter elements. Thelocking shutter is pivotal about a pivot pin 10980 extending between theocclusal tie wings 10918 and accommodated by recesses 10997 therein. Aspring 10985 is welded to the pivot pin 10980 and is also trappedbetween the shutter elements 10981.

In the closed condition, the locking shutter 10924 is biased by thespring 10985, which acts on the pivot pin 10980, into notches 10987formed in the occlusal surfaces of the gingival tie wings 10916. When itis desired to release the locking shutter 10924 and move it to an opencondition, it is necessary to apply an occlusally directed force on thelocking shutter to compress the spring 10985 and move the lockingshutter occlusally allowing the gingival end of the locking shutter toclear the notches 10987 and pivot to the open condition. Closing thelocking shutter is achieved by performing the above steps in reverse.

Referring now to FIGS. 102 and 103, still yet another embodiment of anorthodontic bracket is shown and is generally indicated to by referencenumeral 20010. The orthodontic bracket includes a locking shutter 20024having a single loop at one end surrounding a pivot pin 20080 extendingbetween the occlusal tie wings 20018. The locking shutter 20024 ispivotal about the pivot pin 20080 between open and closed positions. Alocking mechanism is provided on the orthodontic bracket to retain thelocking shutter 20024 in the closed condition. The locking mechanismincludes an L-shaped arm 20025 extending from the free end of thelocking shutter. A wedge 20027 is provided on the locking shutteradjacent the free end. The L-shaped arm and wedge define a channel20029.

An inverted U-shaped stop 20031 is provided on the body 20012 in theinterwing region. The stop 20031 is accommodated by the channel 20029when the locking shutter 20024 is in the closed condition. In thiscondition, the resilient nature of the locking shutter brings the wedge20027 into abutment with the stop 20031 to maintain the locking shutterin the closed condition. To open the locking shutter, an occlusallydirected force is applied to the L-shaped arm to flex the lockingshutter and slide the wedge 20027 beyond the stop 20031 allowing thelocking shutter to pivot to the open condition.

Referring now to FIG. 104, still yet another embodiment of a body for anorthodontic bracket is shown and is generally indicated to by referencenumeral 20112. In this embodiment, the body 20112 and mounting pad (notshown) are shaped to deflect food debris and plaque mesially anddistally away from the orthodontic bracket in the direction of arrows20113. Specifically, the gingival surface of the body is rounded and isgenerally egg-shaped. The occlusal surface of the body 20112 isundulated and has a central formation 20115 thereon defining a pair ofcurved lateral faces 20117. This body design can be used with any of thedescribed orthodontic brackets.

Referring now to FIGS. 105 and 106, still yet another embodiment of anorthodontic bracket is shown and is generally indicated to by referencenumeral 20210. In this embodiment, each gingival tie wing 20216 has aspring-loaded piston 20291 therein. The piston heads 20293 extendoutwardly of the gingival tie wings into the interwing region 20219 andconstitute a retainer for the locking shutter 20224 to maintain thelocking shutter in the closed condition. The spring is sealed by a stop20225 located on the lateral side of the bracket. The pistons 20291 mustbe biased into the gingival tie wings in order to pivot the lockingshutter 20224 to the open condition. As will be appreciated, similar tothe embodiments shown in FIGS. 38 to 47, 97 a to 97 c, and 100 a to 103,the locking shutter 20224 includes a single loop surrounding a pivot pinextending between the occlusal tie wings. Although, the pivot pins areillustrated as extending between the occlusal tie wings, those of skillin the art will appreciate that the pivot pin can extend between thegingival tie wings. It should also be appreciated that the lockingshutter may include laterally spaced, single loops to surround the pivotpin or pivot pins at laterally spaced mesial and distal locations.

If desired, a lubricating or sealing agent can be applied to the body,locking shutter and/or archwire of the previously described orthodonticbrackets.

The orthodontic brackets described above can be formed of any suitablematerial such as ceramic, plastic or other cosmetic material. Ifappropriate, the archwire slot may be constituted by a metallic insertaccommodated by the body of the orthodontic bracket. Likewise in thecase of the embodiment shown in FIGS. 99 a and 99 b, the vertical slotsaccommodating the spring member 10732 may also be defined by a metallicinset accommodated by the ceramic body of the orthodontic bracket.

When the orthodontic brackets are to be used to form braces, it ispreferred that pre-engaging twin orthodontic brackets of one of thetypes illustrated herein be used and attached to the central and lateralteeth and first and second molars and that single orthodontic bracketswithout wings (not shown) be used and applied to the cuspid and premolarteeth. This system of orthodontic brackets provides advantages in thatthe nature of the single orthodontic brackets are easier to bond to theposterior crowns of the cuspid and premolar teeth. Also, the singleorthodontic brackets provide greater interbracket distances allowing forgreater archwire flexibility in the posterior middle regions, cuspidsand premolars. Better rotational control is however maintained with theuse of the twin pre-engaging orthodontic brackets on the central andlateral teeth and first and second molars.

Although a number of embodiments of orthodontic brackets have beendisclosed, those of skill in the art will appreciate that othervariations and/or modifications may be made to the present inventionwithout departing from the scope thereof as defined by the appendedclaims.

1. An orthodontic bracket comprising: a body having a lingual surfacefor attachment to a tooth, the body defining and arch wire slotextending mesiodistally across the body and dimensioned to receive anarch wire wherein the body includes a recess; a shutter coupled to thebody and moveable relative to the body between an open position, inwhich placement and removal of an arch wire in the arch wire slot isfacilitated, and a closed position, in which placement and removal of anarch wire in the arch wire slot is inhibited; and a spring positioned inthe recess and coupled to the body, the spring providing a force to biasthe shutter toward the closed position.
 2. An orthodontic bracket asclaimed in claim 1 wherein the body includes a tie wing and wherein therecess is formed in the tie wing.
 3. An orthodontic bracket as claimedin claim 2 wherein the tie wing is an occlusal tie wing.
 4. Anorthodontic bracket as claimed in claim 2 wherein the body includes asecond tie wing having a second recess and a second spring positionedwithin the recess, wherein the second spring is coupled to the shutter.5. An orthodontic bracket as claimed in claim 1, wherein the springbiases the shutter toward the closed position.
 6. An orthodontic bracketas claimed in claim 5 wherein the body includes a notch adapted toengage and hold the shutter in the open position.
 7. An orthodonticbracket as claimed in claim 1 wherein at least a portion of the shutterslides within the recess.
 8. An orthodontic bracket as claimed in claim1 wherein the spring comprises a coil spring.
 9. An orthodontic bracketcomprising: a body having a lingual surface for attachment to a tooth,the body defining an arch wire slot extending mesiodistally across thebody and dimensioned to receive an arch wire, wherein the body includesa tie wing and a recess formed in the tie wing; a shutter coupled to thebody and moveable relative to the body between an open position, inwhich placement and removal of an arch wire in the arch wire slot isfacilitated, and a closed position, in which placement and removal of anarch wire in the arch wire slot is inhibited; and a spring positioned inthe recess and coupled to the body, the spring providing a force to biasthe shutter.
 10. An orthodontic bracket as claimed in claim 9 whereinthe tie wing is an occlusal tie wing.
 11. An orthodontic bracket asclaimed in claim 9 wherein the body includes a second tie wing having asecond recess and a second spring positioned within the recess, whereinthe second spring is coupled to the shutter.